Objectives This tutorial shows you how to define data for and run a rational method model for a watershed in Orange County.

Transcription

1 v. 9.0 WMS 9.0 Tutorial Modeling Orange County Rational Method GIS Learn how to define a rational method hydrologic model for Orange County (California) from GIS data Objectives This tutorial shows you how to define data for and run a rational method model for a watershed in Orange County. Prerequisite Tutorials Watershed Modeling Advanced DEM Delineation Techniques Required Components Data Drainage Map Hydrology Hydrologic Models Time minutes Page 1 of 12 Aquaveo 2012

2 1 Contents 1 Contents Introduction GIS Data Open Project File Global Job Control Parameters Sub-area Parameters Initial sub-area parameters Compute Losses Concentration Point (Reach) Data Running the Simulation Introduction WMS has many features and tools that will help you to get the most use out of digital terrain and GIS data for delineating sub-areas and computing loss rates. This exercise demonstrates how to use WMS to use GIS data to automate rational and unit hydrograph analyses and shows how to compute Orange County loss rates (Fm and Ybar) with soil type and land use GIS data. Refer to the following tutorials in the standard WMS tutorials for an in depth treatment of GIS data: Images (2 Introduction-Images) Basic Feature Objects (3 Introduction-BasicFeatureObjects) Advanced Feature Objects (6 Introduction-AdvancedFeatureObjects) Time of Concentration Calculations and Computing a Composite CN (9 WatershedModeling-TimeConcAndCN) 3 GIS Data 3.1 Open Project File 1. Close all instances of WMS 2. Open WMS 3. Select File Open 4. Locate the OrangeCounty\Rational folder in your tutorial files. If you have used default installation settings in WMS, the tutorial files will be located in \My documents\wms 9.0\Tutorials\. 5. Open NewlandGIS.wms 6. Toggle off the Land Use and Soil Type coverages in the Project Explorer Page 2 of 12 Aquaveo 2012

3 7. Select the Frame macro This WMS project file includes GIS data stored in three different coverages: Drainage, Land Use, and Soil Type. The geometric properties of the sub-areas and reaches were already computed using the Drainage coverage and stored in the WMS project file. Figure 3-1 shows the drainage coverage and the area calculated for each sub-area. Figure 3-1: Newland drainage coverage 1. Select Display Display Options 2. Select Drainage Data and toggle off Basin Areas 3. Select OK 4 Global Job Control Parameters Before running a model, the global parameters must be set. These parameters include the return-period of the storm event and whether or not an expected value analysis is being run. These parameters can be set in the Job Control dialog (Figure 4-1). 1. Switch to the Hydrologic Modeling module 2. Make sure the Model combo box is set to OC Rational Page 3 of 12 Aquaveo 2012

4 3. Select OC Rational Job Control Figure 4-1: Job Control dialog 4. Change the Frequency to 100-year 5. Toggle on Expected value 6. Select OK 5 Sub-area Parameters A model is now ready to be set up and run. By double-clicking a sub-area symbol, or a concentration point symbol, the Orange County Rational Method Edit Parameters dialog will appear, allowing for the editing of the sub-area/concentration point attributes. 5.1 Initial sub-area parameters 1. Use the Zoom tool to zoom in to the area shown in the upper right corner of Figure 5-1 Page 4 of 12 Aquaveo 2012

5 Figure 5-1: Zoom to first initial sub-area 2. Use to Select Basin tool to double-click on the sub-area labeled 101B The Orange County Rational Method - Edit Parameters dialog, shown in Figure 5-2, will open. Figure 5-2: Orange County Rational Method - Edit Parameters dialog 3. Click the Compute button in the Initial sub-area section of the dialog. This calculates the time of concentration for the initial sub-area. The Initial Sub-area Tc dialog (Figure 5-3) will appear. Page 5 of 12 Aquaveo 2012

6 Figure 5-3: Initial Sub-area Tc dialog 4. Change Land use type to Multi Family: Condos 5. Verify that the % impervious value is 65 Once the percent impervious value is selected, the corresponding K value will be automatically updated. The K value is a coefficient that depends on the land use type and percent impervious. 6. For L enter For H enter Select OK The intensity value will automatically be calculated using the new time of concentration and the value contained in the Mountain fraction edit field. This field, located just below the area data, allows the user to enter in the decimal fraction of the area which is above 2000 ft. The Compute button, located next to this data, calculates this value using digital terrain data, if it exists. The intensity value is updated as these values are changed. 9. Select Done 10. Select the Frame macro 11. Use the Zoom tool to zoom in to the area shown in the upper middle portion of Figure 5-4 Page 6 of 12 Aquaveo 2012

7 Figure 5-4: Zoom to second initial sub-area 12. Use to Select Basin tool to double-click on the sub-area labeled 201B 13. Click on the Compute button in the Initial sub-area section of the dialog 14. Change Land use type to Single Family: > 10 dwell/acre 15. For L enter For H enter Select OK 5.2 Compute Losses Notice that there are two buttons in the Losses section of the dialog, one labeled Compute and the other one labeled Compute GIS. The Compute button will allow for the computation of composite loss values by multiplying all ap (pervious area fraction) values with their corresponding Fp (maximum effective pervious area loss rate) values for the specified areas. The Compute GIS button will allow for the computation of composite loss value by using the Soil Type and Land Use data in the Compute GIS Attributes calculator. The computer automatically calculates composite ap and Fp values for each of the sub-basins as well as the corresponding Fm values. 1. Click on the Compute GIS button in the Losses section of the dialog Page 7 of 12 Aquaveo 2012

8 2. Verify that the Soil Type coverage will be used for determining soil type and the Land Use coverage will be used for determining land use 3. Click on the Import button 4. Open ocland.tbl 5. Select OK to compute loss parameters for all basins 6. Choose a filename for saving the GIS loss calculation details and select Save The GIS calculator computes loss rates by overlaying the soil type and land use coverages with the drainage coverage and using the Fp values associated with each soil type and percent impervious values in the land use mapping table to compute composite Fm loss values. The composite loss values are calculated and displayed in the Edit Parameters dialog. (Figure 5-5) Figure 5-5: OC Rational Method - Edit Parameters dialog Losses are computed for all sub-areas when you calculate losses using GIS attributes, but you can always enter other loss values and compute a new Fm for individual sub-areas. 6 Concentration Point (Reach) Data 1. Select the concentration point labeled 201 (you may need to move the Orange County Rational Method Edit Parameters dialog in order to view and select the concentration point) Page 8 of 12 Aquaveo 2012

9 Notice that only the Reach Data section of the dialog (Figure 6-1) is accessible. Figure 6-1: OC Rational Method - Edit Parameters dialog 2. Toggle on the checkbox next to 3. Change Conveyance Type to The different variables associated with the channel type will be displayed in a spreadsheet-type edit box and can be edited if necessary in the appropriate fields. There is also a checkbox which allows the user to specify whether the flow is on one side of the street or not. 4. For Up elevation enter For Down elevation enter For Pipe diameter enter For Manning s n enter Page 9 of 12 Aquaveo 2012

10 8. For Minor loss energy factor enter Continue to edit reach data by selecting each of the concentration points and entering parameters using Table 6-1. For point 120 there is no need to input any parameters since it is the most downstream node and we are not doing any routing that point further. You may need to move the Orange County Rational Method Edit Parameters dialog around and/or use the zoom and pan tools (middle scroll button on mouse) in order to select other concentration points. Table 6-1: Concentration point (reach) parameters Conc. point Description Up elev Down elev Other parameters Above ground Half width = 30.0; Gradebreak = 20.0 Industrial local Toggle on Flow on one side Diameter = 18.0; Manning's n = Diameter = 30.0; Manning's n = Diameter = 36.0; Manning's n = Diameter = 30.0; Manning's n = Diameter = 36.0; Manning's n = Diameter = 60.0; Manning's n = Diameter = 63.0; Manning's n = Diameter = 60.0; Manning's n = Diameter = 69.0; Manning's n = Diameter = 78.0; Manning's n = Diameter = 78.0; Manning's n = Diameter = 87.0; Manning's n = Diameter = 84.0; Manning's n =.013 Above ground b = 9.0; h = 10.0 Trapezoidal channel Manning's n = Above ground b = 11.0; h = 12.0 Trapezoidal channel Manning's n = Above ground b = 12.0; h = 12.0 Trapezoidal channel Manning's n = Above ground b = 11.0; h = 12.0 Trapezoidal channel Manning's n = Page 10 of 12 Aquaveo 2012

11 Conc. point Description Up elev Down elev Other parameters Above ground b = 12.0; h = 13.0 Trapezoidal channel Manning's n = Diameter = 18.0; Manning's n = Diameter = 27.0; Manning's n = Diameter = 33.0; Manning's n = Diameter = 42.0; Manning's n = Diameter = 57.0; Manning's n = Diameter = 54.0; Manning's n = Diameter = 57.0; Manning's n = Diameter = 90.0; Manning's n = b = 7.0; h = 8.0; Manning s n = Box culvert 10. Select Done 7 Running the Simulation 1. Select OC Rational Tree Mapping 2. Select Concentration point Select Sub-area 115B Page 11 of 12 Aquaveo 2012

12 4. Click on the map ( ) button 5. Select OK 6. Select OC Rational Run Simulation 7. Enter the file name for the detailed output and click Save Page 12 of 12 Aquaveo 2012